org.apache.tools.ant.util.optional.JavaxScriptRunner Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tools.ant.util.optional;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.function.BiConsumer;
import java.util.stream.Collectors;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.SimpleBindings;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.MagicNames;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.JavaEnvUtils;
import org.apache.tools.ant.util.ScriptRunnerBase;
/**
* This class is used to run scripts using JSR 223.
* @since Ant 1.7.0
*/
public class JavaxScriptRunner extends ScriptRunnerBase {
private ScriptEngine keptEngine;
private CompiledScript compiledScript;
/**
* Get the name of the manager prefix.
* @return "javax"
*/
@Override
public String getManagerName() {
return "javax";
}
/** {@inheritDoc}. */
@Override
public boolean supportsLanguage() {
if (keptEngine != null) {
return true;
}
checkLanguage();
ClassLoader origLoader = replaceContextLoader();
try {
return createEngine() != null;
} catch (Exception ex) {
return false;
} finally {
restoreContextLoader(origLoader);
}
}
/**
* Do the work to run the script.
*
* @param execName the name that will be passed to the
* scripting engine for this script execution.
*
* @exception BuildException if something goes wrong executing the script.
*/
@Override
public void executeScript(String execName) throws BuildException {
evaluateScript(execName);
}
/**
* Do the work to eval the script.
*
* @param execName the name that will be passed to the
* scripting engine for this script execution.
* @return the result of the evaluation
* @exception BuildException if something goes wrong executing the script.
*/
public Object evaluateScript(String execName) throws BuildException {
checkLanguage();
ClassLoader origLoader = replaceContextLoader();
try {
if (getCompiled()) {
final String compiledScriptRefName =
String.format("%s.%s.%d.%d", MagicNames.SCRIPT_CACHE,
getLanguage(), Objects.hashCode(getScript()),
Objects.hashCode(getClass().getClassLoader()));
if (null == compiledScript) {
compiledScript = getProject().getReference(compiledScriptRefName);
}
if (null == compiledScript) {
final ScriptEngine engine = createEngine();
if (engine == null) {
throw new BuildException(
"Unable to create javax script engine for %s",
getLanguage());
}
if (engine instanceof Compilable) {
getProject().log("compile script " + execName,
Project.MSG_VERBOSE);
compiledScript =
((Compilable) engine).compile(getScript());
} else {
getProject().log(
"script compilation not available for " + execName,
Project.MSG_VERBOSE);
compiledScript = null;
}
getProject().addReference(compiledScriptRefName,
compiledScript);
}
if (null != compiledScript) {
final Bindings bindings = new SimpleBindings();
applyBindings(bindings::put);
getProject().log(
"run compiled script " + compiledScriptRefName,
Project.MSG_DEBUG);
return compiledScript.eval(bindings);
}
}
ScriptEngine engine = createEngine();
if (engine == null) {
throw new BuildException(
"Unable to create javax script engine for "
+ getLanguage());
}
applyBindings(engine::put);
return engine.eval(getScript());
} catch (BuildException be) {
//catch and rethrow build exceptions
// this may be a BuildException wrapping a ScriptException
// deeply wrapping yet another BuildException - for
// example because of self.fail() - see
// https://issues.apache.org/bugzilla/show_bug.cgi?id=47509
throw unwrap(be);
} catch (Exception be) {
//any other exception? Get its cause
Throwable t = be;
Throwable te = be.getCause();
if (te != null) {
if (te instanceof BuildException) {
throw (BuildException) te;
} else {
t = te;
}
}
throw new BuildException(t);
} finally {
restoreContextLoader(origLoader);
}
}
private void applyBindings(BiConsumer target) {
Map source = getBeans();
if ("FX".equalsIgnoreCase(getLanguage())) {
source = source.entrySet().stream()
.collect(Collectors.toMap(e -> String.format("%s:%s", e.getKey(),
e.getValue().getClass().getName()), Map.Entry::getValue));
}
source.forEach(target);
}
private ScriptEngine createEngine() {
if (keptEngine != null) {
return keptEngine;
}
if (languageIsJavaScript()) {
maybeEnableNashornCompatibility();
}
final ScriptEngine result =
new ScriptEngineManager().getEngineByName(getLanguage());
if (result == null && JavaEnvUtils.isAtLeastJavaVersion("15")
&& languageIsJavaScript()) {
getProject()
.log("Java 15 has removed Nashorn, you must provide an engine "
+ "for running JavaScript yourself. "
+ "GraalVM JavaScript currently is the preferred option.",
Project.MSG_WARN);
}
maybeApplyGraalJsProperties(result);
if (result != null && getKeepEngine()) {
this.keptEngine = result;
}
return result;
}
private static final String DROP_GRAAL_SECURITY_RESTRICTIONS = "polyglot.js.allowAllAccess";
private void maybeApplyGraalJsProperties(final ScriptEngine engine) {
if (engine != null && engine.getClass().getName().contains("Graal")) {
engine.getBindings(ScriptContext.ENGINE_SCOPE)
.put(DROP_GRAAL_SECURITY_RESTRICTIONS, true);
}
}
private static final String ENABLE_NASHORN_COMPAT_IN_GRAAL = "polyglot.js.nashorn-compat";
private void maybeEnableNashornCompatibility() {
if (getProject() != null) {
System.setProperty(ENABLE_NASHORN_COMPAT_IN_GRAAL,
Project.toBoolean(getProject().getProperty(MagicNames.DISABLE_NASHORN_COMPAT))
? "false" : "true");
}
}
private final static List JS_LANGUAGES = Arrays.asList("js", "javascript");
private boolean languageIsJavaScript() {
return JS_LANGUAGES.contains(getLanguage());
}
/**
* Traverse a Throwable's cause(s) and return the BuildException
* most deeply nested into it - if any.
*/
private static BuildException unwrap(Throwable t) {
BuildException deepest =
t instanceof BuildException ? (BuildException) t : null;
Throwable current = t;
while (current.getCause() != null) {
current = current.getCause();
if (current instanceof BuildException) {
deepest = (BuildException) current;
}
}
return deepest;
}
}